1. Field
One embodiment of the invention relates to a light-emission control device that controls light emission of a light emitter, and a liquid-crystal display apparatus with the light-emission control device.
2. Description of the Related Art
Currently available televisions, personal computers, mobile phones, etc. are generally equipped with a liquid-crystal display apparatus that displays images. Such a liquid-crystal display apparatus includes a liquid crystal panel, which by itself does not emit light but is illuminated by a light emitter, such as a backlight, located behind it.
Some conventional liquid-crystal display apparatuses with backlight are configured with a view to reducing power consumption. In such a configuration, the display screen is associated with light sources that constitute the backlight and divided into a plurality of areas (screen areas), and the light sources are controlled area by area.
Among this type of liquid-crystal display apparatuses is the one disclosed in Japanese Patent Application Publication (KOKAI) No. 2004-191490. This liquid-crystal display apparatus calculates the maximum luminance of each screen area based on input video signal, and causes the light source in each screen area to emit light based on the maximum luminance, and corrects luminance information supplied to a liquid crystal panel.
In a liquid-crystal display apparatus that controls the light sources area by area, a light value at which each light source is lit and the transmittance of each liquid crystal element forming the liquid crystal panel are correlated to control the luminance of the liquid crystal panel to a desired value.
However, even if the light value at which each light source is lit and the transmittance of each liquid crystal element of the liquid-crystal panel are correlated, a video image with sharp brightness variation (e.g., a video image which is predominantly dark with a small area of light) cannot be displayed with appropriate luminance.